Terminal structure for double-ended lamps



p 1961 F. A. MOSBY 3,001,096

TERMINAL STRUCTURE FOR DOUBLE-ENDED LAMPS Filed July 2, 1959 ITWVTWTOTT "Ffecievick A. M0510 8 His A t t zweg.

3,001,096 TERMINAL STRUCTIIJJRE IgOR DOUBLE-ENDED Frederick A. Mosby, Cleveland, Ohio, assignor to General Electric Company, a corporation of New York Filed July 2, 1959, Ser. No. 824,498

3 Claims. (Cl. 313-318) This invention relates to electric lamps comprising a sealed envelope of vitreous material containing electric energy translation means such as a filament or electrodes, and more particularly to base and terminal structures for double-ended lamps having a base at each end for supporting the lamp in spaced terminals of a socket and conducting current thereto.

It is among the objects of the invention to provide a base and terminal structure of low cost, sturdy construction, accurately prefocused design and possessing freedom from electrical shock hazard.

In accordance with one aspect of the invention, there is provided a terminal structure wherein the lead-in conductors extend from opposite ends of the envelope through pinch seals of I-shaped cross section, and contact members are carried by the external portions of the leadin conductors at the outer ends of the respective pinch seals and are enclosed by, and recessed in, a tubular insulating base member which has a diametrally slotted end portion snugly fitted over the web portion of the I-shaped pinch seal and confined between the sides or flanges there of. In accordance with a further aspect of the invention, the outer faces of said contact members are of concave spherical contour, and the contact members are axially aligned with the filament or energy translation means so that they serve as an electrical connection to the filament and also as a means of focusing the lamp in a socket of suitable design having opposed probe-like terminals with rounded ends which engage the concave faces of said contact members.

Further features and advantages of the invention will appear from the following detailed description and from the drawing wherein:

FIG. 1 is a plan view of an electric lamp having a base and terminal structure in accordance with the invention;

FIG. 2 is an exploded perspective view of one end of the lamp and base member;

FIG. 3 is a longitudinal section through one end of the lamp;

FIG. 4 is a transverse section along the line 4-4 in a FIG. 3; and

FIGS. 5 and 6 are fragmentary plan views of an end of two lamps of different size having pinch seal portions of diiferent sizes and slightly modified to properly receive base members of the same size.

Referring to FIG. 1 of the drawing, the lamp shown therein comprises a tubular envelope 1 of vitreous material such as quartz or glass and containing an energy translation means in the form of an axially disposed filament 2 of coiled tungsten wire. The filament 2 is supported by and electrically connected at each end to a lead-in conductor 3 having an extremely thin intermediate foliated section 4 hermetically sealed in a pinch seal portion 5 at the end of the envelope. When the envelope 1 is of quartz, the foliated portion 4 and the outer end nit sa ?;a

; 2 portions of the conductors 3 may be of molybdenum, and the inner end portions of the conductors may be of tungsten. The envelope may also contain a filling of rare gas such as argon and a small quantity of iodine as disclosed and claimed in Patent 2,883,571, Fridrich et al.

The external portion of each of the lead-in wires 3 carries a contact member 6 (FIGS. 2 and 3) which may consist of a cylindrical slug of nickel having an axially offset tab 7 projecting from the rear face thereof and welded to the lead wire 3. The front or outer face 8 of the contact member 6 is preferably of concave spherical contour and it serves as an electrical connection between the filament 2 and a socket, and as a focusing device when used in a socket of proper design. Focusing is accomplished by aligning the axes of the contact member 6 with that of the filament 2 when welding the contact members to the lead wires 3. Opposed probe-like socket terminals having rounded ends are biased toward each other to fit the concave faces 8 of the contact members and properly align the lamp in a fixture.

Each of the contact members 6 is enclosed by, and recessed in, a tubular base member 9 of suitable insulating material, preferably a ceramic material. For mounting the base member 9 on the lamp, the pinch seal 5 is accurately formed to an I-shaped cross section to snugly receive and properly position the base. The base memher 9 is a cylindrical shell having a diametral slot 10 extending longitudinally from one end thereof and defining leg portions 11 which snugly straddle the web portion 12 of the I-shaped seal 5 and fit snugly between the sides of the channel portions 13 at each side of the web portion. The base member 9 is preferably securely fixed to the end of the lamp by a quantity of basing cement 14.

In FIG. 5 there is shown a pinch seal portion 5a like that shown at 5 in FIGS. 1 to 4 but for a lamp of larger size than that shown in FIGS. 1 to 4 and therefore having a seal 5a of greater width than the seal 5. In this case, in order to accommodate the same universal size of base 9, the end portions 15 of the flanges of the I-shaped section are made thicker to thereby reduce the width of the channel portion of the I-shaped section to snugly accommodate the end leg portions 11 of the base member 9. Conversely, in FIG. 6 the end portions 16 of the flanges of a pinch seal of smaller size are reduced in thickness to thereby increase the width of the channel portions to properly accommodate the end leg portions 11 of the same size base member 9.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An electric lamp comprising a sealed envelope of vitreous material containing electric energy translation means and having an external pinch seal portion at opposite ends thereof and a lead-in conductor extending therethrough from said energy translation means, said seal portions having substantially an I shape in cross section with accurately formed channels at each side of the web portion of the I-shaped section, a contact member carried by each of said lead-in conductors at the outer end of the respective pinch seal portion, and a tubular base member of insulating material at each end of the lamp and having a diametrically slotted end portion snugly straddling the said web portion of the pinch seal and fitting snugly between the sides of the channel portions of said pinch seal, said base member surrounding the aslatented Sept. 19, 196i contact and extending beyond said contact, and means securing said base member to said pinch seal.

2. A lamp as set forth in claim 1 wherein said securing means comprises a quantity of cement.

3. A lamp as set forth in claim 1 wherein the electric energy translation means is a filament extending axially of the envelope and said contact members have outer faces of concave spherical shape and have their axes aligned with that of the filament.

UNITED STATES PATENTS Howell Mar. 5, Penin Mar. 30, Terrill Oct. 15, Hodge Mar. 29, Thomas July 21,

FOREIGN PATENTS Germany J an. 7, 

